Filter



Dec. E79 1935, E. CQCKS ET AL 924,719

FILTER Filed Jan. 31, 19:55 3 sheets-sheet l ET TUHNEIS* ea, ETC 1935. E. cocks ET AL FILTER 3 SheetS-Sheeb 2 Filed Jan. 51, 1935 JITVENTUHS 7L-1E' UJIXE *LEMCEWN ET TUENEIS.

Patented Dec. 17, 1935 UNITED STATES PATENT OFFICE FILTER AApplication January 31, 1933, Serial No. 654,375

3 Claims. (Cl. 210-183) This invention relates to improvements in filters and particularly to those forms of filters which utilize a finely divided material, such as diatomaceous or infusorial earth carried by the 5 fluid against a screen on which the material collects and through which the fluid is caused to pass during the filtering operation. Heretofore filters have been designed using screens and diatomaceous or infusorial earth has been introduced into the fluid to be ltered and carried thereby against the screen. When a layer of diatomaceous earth on the screen has been impregnated with dirt or foreign matter, the customary practice was to introduce additional l5 infusorial earth into the fluid and. thus form a new coating on the screen over the old coating. Due to vibration and rother causes, such as for example the cells of the diatomaceous earth becoming impregnated with dirt or being loaded 2o with water when some other fluid was being filtered, the diatomaceous earth is apt to drop off of the screen and collect in the bottom of the filtering chamber where in prior constructions it was allowed to remain as an inert mass until there was occasion to replace all of the diatomaceous earth in the filter with new diatomaceous earth. This permitting of the dropped powder to collect and remain in the bottom of the filtering chamber was not only wasteful but it reduced the efficiency of the filter.

An object of the present invention is to provide an improved form of filter wherein provision is made for continuously or at frequent intervals agitating the fluid in the bottom of the filter chamber so as to throw whatever powder collects there into suspension in the fluid so that it will be carried by the fluid against the screens.

The arrangement is such as to prevent or greatly retard the collection of any infusorial earth or powder n the bottom of the filter chamber and to keep it in suspension in the liquid so that it will be carried against the screens.

In prior practice also a layer of diatomaceous or infusorial earth was first built against the screen, following which filtering action took place. Dirt to be filtered out of the fluid collected on the outside of the laye. of diatomaceous earth and as this layer of dirt built up an increase in pressure in the filter was noticeable. On introducing additional diatomaceous earth to build up a second layer on the screens,

the pressure in the filter was not greatly reduced. Furthermore the interior of any layer of diatomaceous earth beneath the layer of dirt 5 would not be utilized to any great extent inasmuch as it is the outermost surface of diatomaceous earth that does most of the filtering. Consequently in prior constructions it was necessary at relatively frequent intervals to renew the diatomaceous earth used in the filter. 5

Another object of the present invention is to provide a filter wherein provision is made for quickly producing a reversal of flow through the filter to force all of the diatomaceous earth off of the screens, including the layer or layers of dirt 10 on the layers of diatomaceous earth. In this way, by causing the fluid to reverse its flow and remove the diatomaceous earth from the screens, the agtating mechanism can cause the diatomaceous earth to be thrown into suspen- 15 sion in the fluid when 'normal operation of the filter is resumed and thus form a new layer of diatomaceous earth against the screens. In this Way a given layer or supply of diatomaceous earth can be used over and over again to produce 20 different or successive layers presenting relatively clean outside surfaces against which the major portion of the filtering action takes place.

With the foregoing and other objects'in View, which will be made manifest in the following 25 detailed description, and specifically pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein: l

Fig. 1 is a view in elevation of an apparatus to 30 be used in conjunction with a washer employed by dry cleaners illustrating the improved filter as forming a part thereof and thus illustrating a practical situation wherein the improved filter may be advantageously employed, it being under- 35 stood that the use of theA improved filter is in no way confined to this apparatm but may be wherever filtering is required.

Fig. 2 is a view in vertical section through the improved filter, essential associated apparatus be- 40 ing somewhat schematically shown.

Fig. 3 is a Vertical section taken substantially upon the line 3 3 upon Figure 2.

Fig. 4 is a horizontal section taken upon the line 4 4 upon Figure 2.

Fig. 5 is a horizontal section taken upon the line 5-5 upon Figure 2.

Fig. 6 is a partial vertical section illustrating a modified form of screen construction forming a part of the improved filter.

Referring to the accompanying drawings, wherein similar reference characters designate similar parts throughout, and referring particularly to Figures 2 to 5, the improved filter comprises a suitable container I0 which provides, on l5 to the illter.

its interior, a filtering chamber II. This containerisnormallyclosedbyaclosureorcover I2 which can be removably secured in place as by hand wheels I3 on hinge bolts Il, see Figure 1. 'I'he cover I2 carries a relief valve Il which is of the conventional type designed to allow air to lbe expelled from the filtering chamber il when the ltering chamber is being filled with a liquid but to close when the liquid level reaches the relief valve and to remain closed until pressure exceeds a predetermined degree, in which event the relief valve acts as a pop-off. Within the filtering chamber a screen unit is disposedand while the construction of this screen unit may vary we prefer to use 'a screen unit made up of two concentric cylindrical screens the outer of which is indicated at I6 and the inner of which is indicated at I1. These screens are of very fine mesh so that diatomaceous earth may be carried thereagainst by the fluid being illtered and caused to build up a layer of diatomaceous earth on the surfaces of the screens. 'Ihe upper ends of the screens are separated by a ring i6 and the screens are held spaced from each other against collapse together by means of a coarse wire mesh or heavy screen I9. The space between the screens, which is partially occupied by the coarse wire mesh I6, communicates with an annular manifold 2l having a diametrical manifold part 2l detachably 'connected to a pipe 22 which enters the ltering chamber II near its bottom. Pipe 22 constitutes one outlet leading from the filter for conveying filtered liquid away from the iilter. A second outlet is provided by pipe 23 which leads to a three way valve 2| in a pipe 25 coming from a washing machine or any other apparatus delivering a supply of uid to be filtered. Pipe 25 leads through the three way valve 24 over to aV motor driven pump 26, the outlet from which is provided by a pipe 21 leading through three way valve 23 Pipe2'lisshownasenteringthe filter container i0 near its top, although the exact location of entrance may vary. On the inside of the container there is a downwardly extending tube 29 having a slip joint at its top with the end of pipe 21. This tube carries wings 33 near its bottom adapted to enter brackets 3l secured to the inside of container Il. Near the upper end of the tube there are brackets 32 secured to the inside of container i6 and a somewhat U shaped bracket 33 is adapted to be positioned against the tube and have its ends inserted between the brackets 32 and the walls of container Il to removably fasten tube 26 in place. Tube 23 carries a rose 3| at its bottom, which is located fairly close to the bottom of container I6, and this rose has distributed perforations therein most of which are directed downwardly against the bottom of container I0.

Outlet pipe 22 is branched, one branch having an air` inlet valve 35 which can be manually operated to allow air to enter the outlet pipe. 36 designates a valve whichcan be used to close outlet pipe 22 but when this valve is open illtered fluid may iiow through outlet pipe 22 and through the valve back to the washer or to the location wherever the filtered liquid is desired.

In the 'form of construction shown in Figures l2 to 5 inclusive the operation and advantages are briefly as follows: In order to start up the illter a suitable supply of diatomaceous earth in a finely divided state is introduced into container I0. The cover I2 is replaced and tightened down and the pump 26 is started in operation. Three way valve 2l is so positioned as to permit iluid toiiowthroughpipe fromthesoureeofsupply andtobepumpedbythepump 26throughpipe 21, through open valve 26, and down through tube26. valvesandmaybeallowedtoremainclosedlmtilthecontainer Ilisillledwith 5 liquidfand the air has been exhausted through relief valve I5. When the container II has been illied with liquid and the air exhausted, outlet valve 36 should be immediately opened to permit fluid to flow through the outlet and delivered to 10 the washer where the filter is used in conjunction with the dry cleaning apparatus. It will be noted that the incoming fluid discharges through the rose 34 against the bottom of container III and throws the diatomaceous earth into suspen- 15 sion in the liquid. The liquid in flowing through the screens into the spme partially occupied by the heavy wire mesh I9 carries the diatomaceous earth against the screens and builds up a layer of this iltering medium thereon. When 20 the ilter is used in conjunction with a washer, the liquid is at firstmerely allowed to circulate through the washer. That is liquid is permitted to be supplied to the washer through outlet pipe 22 and through valve 36 and is allowed to return 2, through pipe 26 and to be recirculated through the ilter. 'Ihe liquid as it through the washer is washed and will quickly clear up during continued operation of the filter indicating that a suitable filtering layer of diatomaceous :an earth has been built up on Vthe screens. The rose 34 acts as a form of agitator in the bottom of container Il, initially agitating the diatomaceous earth in the container and throwing it into suspension in the kliquid sothat it can be carried 35 theiscreens, has a tendency to 'drop or settle 40.

in the bottom of container Il, this continued agitation produced by the issuing or discharging streams of incoming fluid -throws this powder back into suspension in the liquid so as to be again carried against the screens. In this way 45 the incoming iluid by the agitation it produces in the container Il causes thelayer of diatomaceous earth on the screens to be continually formed and preserved. It prevents the collection of any diatomaceous earth in the bottom of con- 5o tainer III..

Continued operation of the iilter causes dirt to form in a layer on the outside or incoming side of the layers of diatomaceous earth on the screen. The interior or outlet side of each layer of di- 55 atomaceous earth while in a condition to be utilized is not available for use because of the layer of dirt on the outside and the fact that most of the illtering action takes place on the surface of the layer. Under these circumstances 60 from time to time it is desired to remove each layer of diatomaceous earth entirely from the screens and cause this same diatomaceous earth t'o be reformed into a new layer, thus etliciently utilizing all of the powder. To accomplish this. 65 three way valve 2l is turned so as to shut oil pipe 25 and connect pipe 23 with pump 26. 'Ihree way valve 23 is also turned so that pipe 21 is connected to pipe 31 which leads to any suitable storage reservoir. When v alve 23 is so turned 7c it closes that portion of pipe 21 which leads to tube 29 and valve 36 and with the valve so positioned the pump is started in operation. With the valve so arranged it will be noted that pipe leading to tube 26 is closed and that outlet pipe 22 is likewise closed. 'I'he pump 28 will then build up a vacuum in container Il on the inlet sides of the screens tendingFto produce a reverse ow through the filter. In'- other words whereas in initial operation fluid will flow from the outside of screen from the insides-of screen `|`1"thr"6ugh itrwith this reverse fiow the pump will tend to draw fluid from the space between the screens outwardly through screen I6 and inwardly through screen I1. -Inasmuch as valve 36 is closed, however, this flow cannot take place and a vacuum is allowed to be built up. W'hen the vacuum is produced, valve 35 constitut-l ing an air inlet is suddenly opened, allowing air to suddenly enter manifold 20'and to enter thel space between the screens. This sudden reverse flow breaks or kicks the layer of diatomaceous earth oif of the screens and by having a cylindrical screen unit made up of concentric screens this sudden supply of air is equally distributed between them so that thereversal of flow through the screens does not become localized at any one place. With the layer of diatomaceous earth thus removed from the screens, it is effec-- tively -mixed and on returning 'the valves to their initial positions -and resuming normal direction of how a newlayer or layers of diatomaceous earth will be formed on the screens, thus causing the filter to operate substantially as efficiently as where new powder is substituted for the entire amount of diatomaceous earth in container I0.

In'this way by destroying a formed layer of diatomaceous earth on the screens and causing the same diatomaceous earth to reform in a new layer, a given supply of diatomaceous earth can be used over and over with practically the same eiilciency as new powder.

'I'he condition of the layers-of diatomaceous earth on the screens can be indicated by a pressure gauge 38, see Figure l, which may be mounted on the `side ofcontainer Ill. When the filter becomes dirty by the formation of a heavy layer of dirt on the layers of diatomaceous earth, the

pressure required to force the liquid through the diatomaceous vearth and through the screens increases, which will be indicated by the pressure gauge. If in the course of continued# runs it is found that the pressure indicated by pressure gauge 38 builds up too quickly, this willuindicate' that all of the diatomaceous earth in container Il has been virtually used up insofar as its nltering efliciency is concerned and that the entire amount of diatomaceousv earth in the container should be replaced with new powder. In this event liquid in the container I8 may be removed therefromv and a suitablehand hole cover 38in the bottom of the container may be removed to facilitate lcleaning out all of the old diatomaceous earth from the container. In Figure 6 a modified form of screen unit is disclosed whereinv a plurality of pairs of concentric screensare used to increase the available; ltering surface. In tlilform of .cpnstruct-ion` the outer pair of filtering screens is indicated by' the reference characters 4 1 M42 which areheld in spaced relation Js'yan intermediate lfilavy vvireLr mesh 43. 'I'he screens of this outer pairfare mounted in a manifold 44 having a diametrical portion 45 connected to the outlet pipe indicated in this gure at 46. A n inner pair of screens is made up of screens 41 and 48, these being concentric and cylindrical also and being likewise spaced .by an intermediateheavy wire mesh 49.l The lower ends of these screens are disposed in a manifold 58 similar to manifold 64 except smaller in size.' This manifold has a 'diametrical portion which is connected as indicated at 52 to the center of diametrical portion' 45 of manifold 444. This construction increases the available filtering surface but at the same time enahlesair to be quickly distributed through both pairs ofscreens when air is admitted to the outlet pipe from the filter to effect a removal of the diatomaceous earth layers on the screens.

Figure 1 illustrates the filter embodying the invention as being incorporated in an apparatusv to be used in conjunction with a dry cleaningv washer'. AIn this figure there is a storage reset-'- voir 55, a still 56, a condenser 51, a cooler 5 8, and

washer is indicated by the same reference charv acter onthis figure. `This pipe leads to the three way valve 24, which in turn is connected to outlet pipe 23. The pump 26 is given the same reference character'in this figure and the pipe 21 leading to the filter is indicated. Three way valve 28 is indicated by the same reference character 28 and pipe 21`leads through this three` way. valve to thetopv of container `Ill and the upper end of tube 29 therein. Pipe 31 leading from the three way valve 28 leads to a three way valve 63 from which pipes 64 and 65 lead, pipe leading through a valve 68 .to the still 56. Pipe 65 enters a pipe 61 coming from still 51 and running over to storage tank 55. Outlet vpipe 22, given the4 same reference character on this 'iigure, is branched as before' having the air inlet valve 35 and valve 36. The branch containing valve 36 leads through cooler 58 and then over to the washer.

6I is opened so as to permit the cleaning solvent inl the storage reservoir 55 torun through the water trap 59 and over to the washer, after which it is closed. The pump is then started up and liquid is returned from the washer through pipe 25, through pipe`24, through pump 26, pipe 21, valve 28, through tube 29 in the lter, and caused to be discharged into the container l0. Valve 36 is left open. The filter container Il) will -flrst be iilled to expel the air through the` relief valve l5 and then sufficient pressure will be developed to force the liquid through .the screens and through the outlet pipe 22. As the liquid flows through the screens it builds up the layer of diatomaceous earth on them, the diatomaceous earth in the bottom of the container being thrown into suspension in the liquidby the liquid discharging through the perforated rose 34. The filtered liquid on passing through outlet pipe 22, valve 36, and cooler 58, is thenreturned to the washer, from which it comes back to the pump through `pipe, 25. ,A continued operation of the apparatus in this condition vwill cause the liquid circulated *through-:the washer to quickly clear up, it being 4n:nrrstoodthat in the rst few minutes of operation the liquid carries some of the diatomaceous earth with it, which is quickly removed during the continued circulation. When the liquid clears up, the washer is in condition to be operated. Whenit is desired toY clean the screens by kicking oif the old' layer of diatomaceous earth thereon,vvalve 36 is closed and valve 28 isvturned so as to connect pipe 21 leading from the pump to connect pipe 31 with pipe 64 leading to the still. Three way valve 2l is turned so as to connect pipe 23 with pump 26 and to shut oil pipe 25. When the pump is then started in operation, it tendslto produce the partial vacuum in container I0 and to discharge whatever liquid is removed therefrom into still 56. Under these conditionsV still 56 merely constitutes a storage reservoir for the liquid while the layers of diatomaceous earth ,arebeing kicked oil! of the screens on suddenly opening air inlet 35 after the vacuum has been generated, The purpose of the other piping illustrated on Figure 1 forms no part of the present invention but will be readily understood by those familiar with the art of dry cleaning apparatus.

From the above described constructions it will be appreciated that an improved illter is provided wherein provision is made for continually agitating the liquid in the illter chamber near its bottom so as to stir up any powder or diatoms.-

ceous earth tending to collect therein and throw-Ar it into suspension in the liquid to be carried by the liquid against the screens. Furthermore provision is made for kicking oil the layers of diatomaceous earth from hthe'f'screens by producing a sudden reversal of flowing and retaining this diatomaceous earth in the filtering chamber and causing it to be thrown back into suspension in the liquid to reform a new layer on the screens, thus prolonging the usefulness and life of a given supply of diatomaceous` earth andenahling clean filter layers toA be easily and quicklyformed.

Various changes may be made in the details of construction without departing from the spirit or scope of the invention as defined by the appended claims.

We claim:

1.' A filter comprising means providing a closed ltering chamber having an inlet and an outlet, screen means in the ltering chamber between the inlet and the outlet, pump means for forcing liquid to be ltered through the illtering chamber, the screenmeans being adapted to have a comminuted material deposited thereon, means for causing the pumpmeans to attempt a reversal of ilow through the screen means, and valve meansin the o'utlet'for shutting the outlet until A at least a partial vacuum is built up by the pump i means in the ltering chamber and then allowing air to suddenly enter the outlet, thus permitting sudden reversal of flow, causing a removal ofthe commlnuted material from the screenmeans to clean the screen means.

2. A filter comprising means providing a closed filtering chamber having an inlet and an outlet. screen means in the filter chamber between the inlet and the outlet adapted to have a comminuted material applied thereto, pump means for 10 forcing liquid to be illtered through the inlet into the illtering chamber, a valve controlled pipe connecting the inlet side of the ltering chamber to the inlet of the pump, valve means for diverting liquid delivered from the pump from 15 the. inlet whereby upon proper manipulation of the valves the pump may be caused to attempt reverse ow througlrthe screen means, and valve means in the outlet for closing the outlet until the pump has built up a partial vacuum in the 20 nltering chamber, and then allowing air to suddenly enter the outlet thus'permitting a sudden reverse ilo'w through the screen means, thus removing the comminuted material therefrom to eil'ect a cleaning of the screen means.

3. A filter comprising means providing a closed ltering chamber4 having an inlet and an outlet, screen means in the ltering chamber between the inlet and the outlet, means providing a storage reservoir, a pump for forcing the liquid to be 30 filtered through the illtering chamber, a pipe leading from the outlet side of the pump, valve means in the pipe for optionally connecting the outlet side of the pump with the inlet to the filter chamber or to the storage reservoir, valved 35 means for optionally connecting the inlet side of the pump with the inlet side of the fllter chamber or a source of liquid to be filtered, the outlet side of the filter chamber having a valve controlled opening for admitting air thereto, and 40 a valve controlling the outlet from the illter chamber whereby upon properr manipulation of the valves the pump may be caused to attempt reverse flow through the screen, means and upon the building up of a suitable vacuum -the air in- 45 let may be opened to suddenly permit reverse ilow to effect cleaning of the screens.

EDGAR COCKS. LEE D. MCGOWN. 

